贵州中三叠世拉丁期兴义动物群云贵龙属一新材料头骨特征  

The cranial characters of a new specimen of Yunguisaurus from Middle Triassic Ladinian Xingyi fauna,Guizhou

作　　者：鲁昊 周敏[2,3] 付宛璐 柴珺[4] LU Hao;ZHOU Min;FU Wanlu;CHAI Jun(School of History,Beijing Normal University,Beijing 100875,China;School of Earth and Space Science,Peking University,Beijing 100871,China;Geological Museum of Peking University,Beijing 100871,China;School of Archaeology and Museology,Beijing 100871,China)

机构地区：[1]北京师范大学历史学院,北京100875 [2]北京大学地球与空间科学学院,北京100871 [3]北京大学地质博物馆,北京100871 [4]北京大学考古文博学院,北京100871

出　　处：《地质通报》2023年第10期1696-1705,共10页Geological Bulletin of China

基　　金：国家自然科学基金国际(地区)合作与交流项目《中生代海生爬行动物三叠纪起源和第一次辐射及其演化-迁移模式研究》(批准号:41920104001);国家重点研发计划《自然遗产价值评估与潜力区筛选》(编号:2016YFC0503301);贵州省科技支撑计划项目(编号:2904【2016】);北京市科技专项-科学技术普及专项《2.48亿年巢湖龙海洋群落及研究过程的VR复原和科学展览》(编号:Z17111000330000);人才培养共建项目-资源共享类项目-北京高校博物馆联盟建设(体制改革项目)-地质博物馆、现代古生物学和地层学国家重点实验室开放课题基金《XRF微区面扫技术在分析三叠纪海生爬行动物化石埋藏环境中的应用》(编号:213102)。

摘　　要：产自欧洲、北美洲和中国三叠纪的纯信龙次亚目,是连接鳍龙类“干群”和“冠群”的关键分子,也是探讨侏罗纪—白垩纪“冠群”蛇颈龙类起源和早期演化的关键环节类群。李氏云贵龙是中国华南地区发现的纯信龙次亚目中较原始的属种,也是目前发现保存最完好、数量最多的纯信龙类,但对其头骨骨骼形态学的认识依然存在不足。贵州兴义中三叠世拉丁期法郎组竹杆坡段中新发现的一件云贵龙完整头骨化石补充了云贵龙的骨骼学信息,如额骨未愈合、枕部存在开放空间等。经详细比较,新材料可能代表了目前发现的5件李氏云贵龙标本中体长最大的个体,推断额骨未愈合这一特征为云贵龙特有的鉴定特征,而非个体成年与否的判断依据。新材料显示,云贵龙的鳞状骨没有后内侧支,存在开放式枕部,同蛇颈龙类相似,指示了三叠纪纯信龙类同蛇颈龙类密切的亲缘关系。The Triassic Pistosauroidea from Europe,North America and China is the key to link the"stem-group"and"crown-group"Sauropterygia,and is important to reveal the origin and the early evolution of Jurassic-Cretaceous"crown-group"Sauropterygia,Plesiosaurus.Yunguisaurus is one of the most primitive genera of Pistosauroidea discovered in South China,with the most well-preserved specimens.However,the cranial osteology of Yunguisaurus is still lack of understanding.A new material of Yunguisaurus,excavated from the Zhuganpo Member(Ladinian)of Falang Formation,Xingyi Fauna in Guizhou Province,provides new detailed cranial information,such as the unfused frontals and the existence of an open space in the occipital region.Detailed comparison shows that the new material is the longest one among the five specimens of Yunguisaurus reported so far,indicating the unfused frontals should be a diagnosis of Yunguisaurus,rather than an ontogenic difference.There is no inner-posterior branch in squamosal of this new material,forming an open occipital part,which is similar to that of Plesiosaurus,indicating a close relationship with this genus.

关 键 词：中三叠世 纯信龙次亚目 云贵龙属 贵州 

分 类 号：P534.51[天文地球—古生物学与地层学] Q915.2[天文地球—地质学]